This continuing project is designed to identify and locate on the chromosomes of inbred rodents specific inherited characteristics. In addition to being utilized in a wide variety of biomedical research, this knowledge can substantially increase the ability of the Genetic Monitoring Unit to perform its basic mission of genetic quality assurance. Major areas of interest include the characterization of genetic traits by biochemical, immunological, and molecular biological techniques as well as chromosome mapping by standard genetic analysis. This genetic characterization is used to explore new animal models of pathogenesis.